There are many known welding-type power supply designs. (Welding-type power supply, as used herein, includes power supplies used in welding, heating cutting, and other similar high current applications.) Some of those designs have an input rectifier, followed by a converter, followed by an output circuit. (See, for example, U.S. Pat. No. 5,783,799, issued to Geissler, Jul. 21, 1998 and U.S. Pat. No. 6,815,639, issued to Geissler, Nov. 9, 2004, both of which are hereby incorporated by reference). Typically, the rectified voltage is provided to a bus (i.e., a conductor or conductors that provides a fixed or varying potential to a variety of components), which is disposed across a capacitor bank. The converter then converts (inverts, boosts, bucks, etc) the bus to a different voltage and current. Some designs, such as U.S. Pat. No. 6,815,639, have a second bus which is further processed by the output circuit, and other designs, such as U.S. Pat. No. 5,783,799, do not.
It is also well know that welding power supply components can become hot during use. Components can be cooled by blowing air past them, but it is also known that blowing air can bring particles past sensitive components, such as integrated circuits, switches, etc., which could damage them. Thus, there are competing concerns—cooling components and keeping components safe from dirt, etc. One known design addresses these competing concerns is shown in U.S. Pat. No. 5,642,260, issued to Sigl, Jun. 24, 1997. That design places heat sinks in a wind tunnel and the sensitive components outside of the wind tunnel.
Higher output welding-type power supplies have a bus bar that also gets very hot. Generally, as the current output rises, the bus bar must be able to dissipate more heat. Prior art designs do not adequately address the design of bus bars to reduce heat so that they do not need to have air blown past them. Bus bar(s), as used herein, can refer to one bar (or bar at one potential), or multiple bars at different potentials, and bar refers to the conductor, not a particular shape).
Accordingly, a welding-type power supply that has a bus bar that can be used at high current without overheating is desirable. Preferably the bus will not require forced air (or other fluid) cooling.